CoCoRaHS

CoCoRaHS is a unique, non-profit, community-based network of volunteers of all ages and backgrounds working together to measure and map precipitation.

Monday, August 31, 2015

Cyclones Aplenty

If you're a tropical weather enthusiast the last week to ten days has been an interesting period. In the Atlantic Danny was briefly a hurricane, but fizzled out pretty quickly and fell apart last Monday in the eastern Caribbean producing heavy rain but not much else. In the wings was Tropical Storm Erika, which in the early stages appeared to be a threat to Florida. However, Erika never did make hurricane strength. It quickly fell apart as strong wind shear and the mountains of Hispaniola combined to weaken it, and the storm dissipated off the northeast coat of Cuba. Erika did bring heavy rain to the Caribbean last week and the remnant trough of low pressure continued to produce heavy rain across Florida and the southeast coast this weekend.

24-hour precipitation for the southeastern U.S. ending the morning of 8/31/2015

A low pressure system that move off the west coast of Africa became Tropical Storm Fred Sunday, Hurricane Fred early this morning, and was downgraded to Tropical Storm this evening. Fred is a small cyclone and likely will be moving into unfavorable upper air conditions in the next few days. Current forecasts call for it to be only a tropical depression by the end of the week.

Forecast track for Fred.

Conditions are even more interesting in the central Pacific, where three hurricanes are spinning.

NOAA GOES-West image of three hurricanes in the Pacific: Kilo (left), Ignacio (middle), and Jimena (right).

Hurricane Kilo is a Category 4 hurricane located several hundred miles east of Wake Island. Hurricane Ignacio is a Category 2 storm (it was a Category 4 storm on Sunday) located about 350 miles east of Honolulu. Hurricane Jimena is another Category 4 storm with peak sustained winds of 145 mph. Ignacio is not expected to directly threaten Hawaii, but it is producing dangerous surf conditions. This is the first time three major hurricanes (category 3 or higher) have been observed over the central Pacific at the same time.

The eye of Hurricane Jimena taken by astronaut Kimiya Yui on the International Space Station

The tropical cyclone activity in the Pacific is being supported by some very warm water. Below is an image of the Pacific sea surface temperature anomaly as of today.

Sea surface temperature anomaly on August 31. The water over which the hurricanes are located is 1.5°C to more than 2.5°C (2.7°F to 4.5°F) above normal.

Finally Tropical Depression 14-E developed in the eastern Pacific and late today was located about 700 miles south of the southern tip of Baja California. It is expected to strengthen to a tropical storm in the next 24 hours and turn to the north.